Penetration, Permeation, Strike-Through: Gown Test Terms Decoded
Quick summary: Penetration, permeation and strike-through are three different ways a liquid or chemical gets past protective clothing, and they are measured by three different ASTM methods. Penetration describes liquid finding a way through a material or a seam. Permeation describes a chemical moving through the material at a molecular level. Strike-through is the everyday term for the outcome both of them are trying to prevent.
An Ontario long-term care home issues a tender for isolation gowns. The specification says fluid resistant. Two suppliers answer. One has a report behind the phrase; the other has a datasheet that repeats the phrase. Both quotations look comparable, and they are not.
The vocabulary is the problem. Protective clothing performance is described with a small number of words that sound like synonyms and behave nothing alike in a test laboratory. Learning the three of them is the fastest way to make a gown quotation legible.
What Does Penetration Mean in Protective Clothing Testing?
Penetration is the physical passage of a liquid through a material, a seam or a closure. It does not require the liquid to dissolve into the material. It travels through pores, gaps between fibres, openings at a seam, or imperfections introduced during manufacture, and it is usually visible on the inner face when the test ends.
ASTM F903 is the method that examines it at the material level. A challenge liquid is held against a specimen in a penetration cell and pressure is applied, and the inner face is inspected for visible liquid. The method is a screening tool: it tells you how a material behaved under defined bench conditions, not how a finished garment will behave on a nurse during a procedure.
Three further methods refine the same idea with different challenges and loading. ASTM F1670 uses synthetic blood and looks for visible liquid penetration. ASTM F1671 replaces the liquid with the bacteriophage Phi-X174 and detects passage of a biological surrogate, which catches movement that the eye would miss. ASTM F1819 applies synthetic blood using a mechanical pressure technique, a different loading approach again. Gowns and drapes are then described in ASTM F2407, the standard specification for surgical gowns intended for use in healthcare facilities.
A detail that catches buyers out is that synthetic blood is not a stand-in with fixed properties. Work published in the Journal of Testing and Evaluation examined the surface tension of synthetic blood used for ASTM F1670 penetration tests, and surface tension affects how readily a liquid wets and passes through a fabric. Two laboratories using nominally the same challenge can produce different results if that variable is not controlled, which is one reason the test report matters more than the headline.
What Does Permeation Mean, and Why Does It Take Longer?
Permeation is a different event. A chemical contacts the outer face of a material, dissolves into it, diffuses through its thickness and emerges on the inner face. No hole is needed. The material is not pierced; it is traversed.
ASTM F739 is the method that measures this under conditions of continuous contact. The result is normally reported as a breakthrough time, the interval before the challenge chemical is detected on the inner side, together with a permeation rate. Breakthrough can take minutes or hours, and it depends on the chemical, its concentration, the material and the temperature.
The practical consequence is that penetration and permeation cannot be covered by one phrase in a specification. A nonwoven gown material with strong penetration resistance will still allow some solvents and some chemicals to pass through given enough contact time. Chemical protection claims belong to the specific chemical and the specific material, which is why permeation data is reported as a table rather than as a badge.
Where Does Strike-Through Fit In?
Strike-through is the clinical word for the outcome. It describes liquid reaching the skin or the clothing underneath a gown. Staff recognise it immediately and infection prevention guidance treats it as an exposure event to be managed.
What strike-through is not is the name of a test method. That mismatch is where tenders go wrong. A supplier can honestly describe a gown as strike-through resistant, and a buyer can still be unable to verify the claim, because no standard defines what the phrase requires. The verifiable version of the same statement names a test and a level.
The level system comes from the AAMI PB70 barrier classification. Levels 1 and 2 rest on impact penetration and hydrostatic pressure testing, while levels 3 and 4 bring in the blood and viral penetration methods described above. When a specification names a level, the tests are implied and the claim becomes checkable.
How Do the Three Terms Line Up?
| Term | What physically happens | Method that measures it | What a report shows |
|---|---|---|---|
| Penetration | Liquid passes through pores, seams or openings | ASTM F903 for liquid; F1670 for synthetic blood; F1671 for bacteriophage; F1819 for mechanical pressure | Pass or fail for visible or biological penetration under the defined challenge |
| Permeation | A chemical moves through the material at a molecular level | ASTM F739 under continuous contact | Breakthrough time and permeation rate for a named chemical |
| Strike-through | Liquid reaches skin or clothing underneath | No standalone method; described through the PB70 level tests | A level assignment backed by the underlying test results |
| Puncture | A sharp object makes a hole | ASTM F1342 for materials; needle-specific methods for sharps | Force required to puncture, reported with the specimen details |
Sampling is the last piece of the vocabulary. When a supplier states that a batch met a requirement, the number of units examined matters. ISO 2859-1 describes sampling procedures for inspection by attributes, and the published work on synthetic blood penetration underlines how much result variability a small sample can hide.
What Should a Buyer Ask for When a Tender Says Fluid Resistant?
- Which standard? F903, F1670, F1671, F1819 or a PB70 level. A named standard turns a phrase into a testable claim.
- Material or garment? Most penetration methods test material specimens. A garment-level claim needs a different basis.
- Which challenge liquid and which conditioning? Textile results depend on how specimens were conditioned, which ASTM D1776 addresses.
- How many specimens? A result on two specimens and a result on twenty are not the same evidence.
- Who ran the test? A third-party laboratory report is easier to rely on than a figure quoted in a brochure.
For day-to-day purchasing, two products cover the common cases. Our Level 1 non-woven fluid-resistant gowns suit routine care tasks where the exposure is light and brief, and our SMMS 40 gsm Level 2 gowns suit settings where a modest fluid volume is expected. Where splatter reaches face height, the anti-fog PET face shield completes the barrier. The isolation gowns collection groups the range, and multi-site orders can be consolidated through the wholesale ordering desk.
Infection prevention guidance applies these products to real tasks rather than to specifications. Public Health Ontario's IPAC core elements checklist sets out what personal protective equipment staff are expected to wear for routine and reprocessing activities, and the same site's reprocessing checklist covers the decontamination room, where gown selection decisions usually get made. Sharps handling, which is a separate hazard with its own rules in Ontario, is summarized by the Canadian Centre for Occupational Health and Safety and addressed in Ontario Regulation 474/07.
References and standards cited
- ASTM F903 Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Liquids (link checked 21 September 2026)
- ASTM F1670 Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Synthetic Blood (link checked 21 September 2026)
- ASTM F1671 Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Blood-Borne Pathogens Using Phi-X174 Bacteriophage Penetration as a Test System (link checked 21 September 2026)
- ASTM F1819 Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Synthetic Blood Using a Mechanical Pressure Technique (link checked 21 September 2026)
- ASTM F739 Standard Test Method for Permeation of Liquids and Gases through Protective Clothing Materials under Conditions of Continuous Contact (link checked 21 September 2026)
- ASTM F2407 Standard Specification for Surgical Gowns Intended for Use in Healthcare Facilities (link checked 21 September 2026)
- ASTM F1342/F1342M Test Method for Protective Clothing Material Resistance to Puncture (link checked 21 September 2026)
- ASTM D1776/D1776M Practice for Conditioning and Testing Textiles (link checked 21 September 2026)
- ISO 2859-1 Sampling Procedures for Inspection by Attributes (link checked 21 September 2026)
- Gown Blood Penetration Testing: ASTM F1670, F1671 and EN 13795 (link checked 21 September 2026)
- ASTM F1342: Puncture Resistance of Protective Clothing Materials (link checked 21 September 2026)
- Ontario Regulation 474/07 (Needle Safety) under the Occupational Health and Safety Act (link checked 21 September 2026)
- Canadian Centre for Occupational Health and Safety — Needlestick and sharps injuries (link checked 21 September 2026)
- Public Health Ontario — IPAC Checklist for Dental Practice: Core Elements (link checked 21 September 2026)
- Public Health Ontario — IPAC Checklist for Dental Practice: Reprocessing (link checked 21 September 2026)
- Health Canada — Medical Devices Regulations (SOR/98-282) (link checked 21 September 2026)
- A Highly Sensitive Assay Using Synthetic Blood Containing Test Microbes for Evaluation of the Penetration Resistance of Protective Clothing Material. Biocontrol Sci. 2016 (link checked 21 September 2026)
- The Surface Tension of Synthetic Blood used for ASTM F1670 Penetration Tests. J Test Eval. 2018 (link checked 21 September 2026)
- Performance of materials used for biological personal protective equipment against blood splash penetration. Ind Health. 2017 (link checked 21 September 2026)
- Hydrostatic Penetration Testing of Protective Glove Materials Using Water and Synthetic Blood. Ann Work Expo Health. 2023 (link checked 21 September 2026)
Buying for a facility rather than a single practice? Request a B2B quote and we will price your volume with Canadian warehouse delivery.
Related Reading
- Sterilization compliance hub — records, indicators and audits
- Learning Hub — clinical and procurement guides
- Case Review: An LTC Facility Rebuilds a Gown Order
- SMMS vs SMS vs Spunbond: Choosing Isolation Gown Material
- Isolation gowns collection
- Level 1 non-woven fluid-resistant isolation gowns
- SMMS 40 gsm Level 2 isolation gowns, 50-pack
- Face shield, anti-fog PET, 24-pack
- Wholesale and multi-site ordering desk
Frequently Asked Questions
What is the difference between penetration and permeation?
Penetration is the movement of a liquid through a material, a seam or a closure by way of pores, gaps or structural imperfections. Permeation is the movement of a chemical through the material itself at a molecular level, and it happens without any visible hole. A gown can resist penetration and still allow a solvent to permeate through it over time.
What does strike-through mean?
Strike-through is the everyday term for liquid reaching the skin or the clothing underneath a gown. It is a clinical description of an outcome rather than the name of a test method, which is why a specification that says "strike-through resistant" without naming a test is difficult to verify.
Which ASTM method covers liquid penetration of gown material?
ASTM F903 is the method for resistance of materials used in protective clothing to penetration by liquids. A challenge liquid is held against the specimen in a penetration cell and pressure is applied, and the inner face is examined for visible liquid. The method is used to screen materials rather than to grade a finished garment.
What is the difference between F1670 and F1671?
Both test materials used in protective clothing under pressure, but with different challenges. F1670 uses synthetic blood and looks for visible penetration of the liquid. F1671 uses the bacteriophage Phi-X174 as a test system for blood-borne pathogen penetration, which lets the test detect passage that would not necessarily be visible to the eye.
Where does ASTM F1819 fit?
F1819 also uses synthetic blood, but applies it with a mechanical pressure technique, which is a different loading approach from the pressure used in F1670. It is used for materials intended for protective clothing and is often cited alongside the other penetration methods rather than instead of them.
How does chemical permeation testing work?
ASTM F739 measures permeation of liquids and gases through protective clothing materials under conditions of continuous contact. The result is usually expressed as a breakthrough time — how long it takes for the challenge chemical to be detected on the inner side of the material — together with a permeation rate. Breakthrough can take minutes or hours depending on the chemical and the material.
How do the AAMI PB70 levels relate to these tests?
The PB70 barrier levels for gowns are assigned from a combination of tests. Levels 1 and 2 rest on impact penetration and hydrostatic pressure testing, while levels 3 and 4 bring in the blood and viral penetration methods. That is why a gown specification should always name the level and the tests behind it, not just the phrase fluid resistant.
What should a buyer ask for when a tender says fluid resistant?
Ask which standard the claim rests on, which level was assigned, which test methods were run, and whether the result applies to the material or the finished garment. Also ask for the conditioning and sampling details, since textile results depend on how specimens were prepared and conditioned under practices such as ASTM D1776.
Last updated: September 2026. CliniEco Medical is a licensed medical device establishment (MDEL #35334).
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